He is a captain on the most recent Patji expedition, commanding one of the Company's large steam-powered, iron-hulled ships.[1] Like previous expeditions, Eusto's team sails from the homeisles to the Pantheon seeking to establish a permanent outpost on Patji, due to the valuable Aviar that live there.[1] Historically, only trappers can survive in the Pantheon due to an array of incredibly dangerous predators, but the Company has new weapons and other technology that originate with the Ones Above. They are able to kill a deepwalker and build a fortress on Patji.[1] Eusto's expedition also brings a large, complex machine that can map the location of Aviar on the island. The crew does not understand the machine and they inadvertently activate it, causing significant distress to the Aviar.[1]

Vathi notes that Eusto was not fond of her presence on the expedition because he was concerned she would usurp his authority.[1]